Contaminated drinking water is frequent and a large problem in many parts of the world, particularly in developing countries. 1.1 billion people are without reliable drinking water and 1.6 billion are lacking electricity. There is a great demand for being able to purify drinking water in a simple way. Following natural disasters, at war and other large catastrophes such as Aids epidemics, which often leaves children without their parents, the problems with purification of water often culminates and causes usually serious diarrhoea diseases. WHO has provided a standard that disinfecting systems have to fulfil in order to be considered acceptable. This standard requires that a system shall manage to treat water with 100000 colon forming bacillus (colony forming units—CFU) of E-coli per 100 ml water and from this produce water less than one (1 part) CFU per 100 ml.
It is previously known apparatuses and methods for purifying drinking water from harmful parasites and micro-organisms, which known apparatuses/methods utilises UV-light and/or heating to a temperature above 60° C. during about 1 h for pasteurization of the water. Natural sunlight contains UV-light and large amounts of heat energy. It is also known, to use simple pieces of cloth to filter out micro-organisms that usually are combined with larger particles. In common with most of the known apparatuses is that they comprises many and expensive components, are relatively complicated and/or have not a suitable construction that ensures a guaranteed purification of the water.
Through EP-A1-1106188 is previously known a container and a method for disinfection of drinking water. The container is preferably shaped of a flexible plastic material, such as a plastic bag. One side of the container comprises a UV-transparent layer and a second side comprises a layer that produces heat at exposure in sunlight. The container comprises a sealable opening that is used for discharging and filling of water.